My Russian neighbors get on my nerves sometimes. One time their stupid dog walked into our house when I had the back door open. For that, I am recommending 20mm shells.
or
12 gauge extended mag pump shotgun with bird shot. Hit somebody in the face with that, and they will leave you alone.

Just kidding.
It all depends on your firearms preference, your resources, and your home.
If you have no worries of over penetration, go with 12 gauge 00 buck if you want.
If you need one-shot-stops without the risk of over penetration, go with a good handgun with self defense/home defense ammo (glaser safety slug, Hornady ballistic tips, etc.)
It all depends on you.